Single coronary artery Left (SCA L)-Right coronary artery arising from mid-left anterior descending coronary artery: New variant of Lipton classification (SCA L-II) diagnosed by computed tomographic angiography.

Isolated single coronary artery (SCA) is a rare anomaly. Current classification of left and right is further classified based on the course of the anomalous vessel. We report two SCA L cases where right coronary artery (RCA) arose from mid-left anterior descending coronary artery (LAD). Our observation is a variation from the current Lipton classification SCA L Type II where RCA arose from left coronary artery before the LAD, in our cases the RCA arose from mid LAD after the first septal perforator. We believe that this variant should be described as SCA L Type II variant 2 (V2) while the original Lipton classification should be described as SCA L Type II variant 1 (V1).